Okay, the GKT is not where you use quotes. When you put your keyword in, below it and just to the right is a box that says "Match Type" with a pulldown menu. The default setting is broad, meaning that the search results that show up will contain all of the works in your keyword phrase, but in any order as well as separated by other words. When you choose the phrase setting, the results you see will be based on the usage of your exact phrase but with additional words added to the beginning or end. When you choose the exact match type, your results will be based on ONLY that exact phrase, no additional words, as-is.

As an aside, the quotes come into play when you're checking your competition... you can think of simply Googling your phrase as the "broad" - meaning it will show results containing all of the words in your keyword phrase, but in any order as well as separated by other words, Googling within quotes as the "phrase", and Googling in brackets as the "exact".